Comparative Performance of Racing Head and Neck Restraints Gregg S. Baker, P.E. General Technical Properties, LLC Orlando, Florida USA (SAE Paper # )

3 Project Resources General Technical Properties, LLC –Intellectual Property Company Patents, Trademarks and Copyrights –Applications since 1987 Biomechanics –Structural implants »Spinal/craniofacial reconstruction systems »Arthroplasty devices (artificial joints) –Linear accelerator targeting systems (radiosurgery) –Electronically controlled implants Fastening systems IC Engine valve designs WEB-based mass customization software

4 Resources (Cont.) Outside Consultants -Rod Henry, P.E. – General Dynamics “High impact devices” -Leon Kazarian, Ph.D. NASA, U.S. Air Force and Navy (ejection seats, carrier landings, helicopter crashes, Shuttle Challenger post mortem) -Wayne State University, Bioengineering Center -Delphi Safety Systems

5 The Safety Progression 1.That’s racing 2.“This should work” 3.Serious efforts

6 Nothing we can do…

7 “Hey ya’ll, watch this!”

Serious (?) Efforts Some Recent Ideas

9 How well do they perform?

10 The First Crash Test George White, 1980

11

Products that have been tested <2004 White Device HANS Hutchens D-Del Isaac Wright Tucker >2004 Isaac Link R3 Hutchens II Hybrid Leatt Brace

13 Previous Efforts SAE paper # , “Sled Test Evaluation of Racecar Head/Neck Restraints” SAE paper # , “Sled Test Evaluation of Racecar Head/Neck Restraints Revisited”

14 SAE paper # , “Sled Test Evaluation of Racecar Head/Neck Restraints” HANS device Hutchens device D-Cel device

15 SAE paper # , “Sled Test Evaluation of Racecar Head/Neck Restraints Revisited” HANS device Hutchens device D-Cel device

16 In the Perfect World… Every product Every test protocol Every load measure

17 Plan B: Get what you can and see what ya got

18 Data Sources Peer-reviewed publications Unpublished raw test data Summary results from manufacturers

19 Data Set Nine products 21 crash tests ~200 summary load measures

20 Test Protocols (30 Degree Offset) Wayne State University Bioengineering Center “NASCAR” test Delphi Safety Systems Test Center execution of SFI Specification 38.1

21 Wayne State 50G decelerating sled w/o head support, w/seat

22 Wayne State Real Time

23 Wayne State Slow Motion

24 Delphi 70G accelerating sled w/o head support, w/o seat

25 Delphi Real Time

26 Delphi Slow Motion

27 Performance Measures Loads -Axial (Tension/Compression) -Shear -Bending Head Gs Composite measures -HIC -Nij, etc.

28 Load Direction

29 Wayne State

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33 SFI 38.1 at Delphi

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38 “Brain Slosh” references SAE Paper # , Brain Injury Prediction for Indy Race Car Drivers Using Finite Element Model of the Human Head, L. Zhang et al

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42 Composite measures Where:

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44

45 What does it all mean? How do we add this up?

46 Possible Options 1.Extend the Nij concept 2.Utilize fundamental stress analysis

47 Option 1 Extended Nij

Option 2 Fundamental Stress Analysis Does the load exceed the strength? If so, we have BSF

49 What’s the Strength? Healthy yo femur/tibia samples at room temp: Ultimate Strength in Tension: MPa Ultimate Strength in Compression: MPa Source: Burstein, A.H. et al, J. Bone Joint Surg., 58A, 82, 1976

50 What’s the Load? 1.Sum “F” and “M” values to determine axial loads. 2.Consider shear to resolve principle loads.

51 Occipital Condyles

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53 Fz Mx

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56 Principle Stresses

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59 Conclusions Performance ~ f(1/length, stiffness) Dampers are magic Engaging the belt retains the belt Classic measures, while valuable, do not tell the whole story There is a significant need for simplification

60 Acknowledgements Rod Henry, General Dynamics George White Jay Wright Wayne State Bioengineering Center Delphi Safety Systems Test Center

61 Thank you